The present invention relates to a solar energy collector system including at least one metal panel having a system of internal tubular passageways disposed between spaced apart portions of the thickness of the panel. A heat exchange medium is circulated through said passageways wherein said panels utilize solar energy for elevating the temperature of the heat exchange medium.
It is well known that the radiation of the sun can be collected as a source of energy for heating or cooling or for direct conversion to electricity. Heating and cooling based on solar energy depend upon collection of rays of solar energy in a fluid heat transfer system. The heated fluid is pumped or allowed to flow to a place of utilization for the thermal energy it has acquired, with a temperature sensing device employed in association with the panel for controlling the circulation of fluid therethrough.
In certain areas of the world, solar energy is the most abundant form of available energy if it can be harnessed economically. Even in more developed areas of the world, the economic harnessing of solar energy would provide an attractive alternative to the use of fossil fuels for energy generation particularly in this era of increased fuel costs.
One of the problems attending the development of an efficient system for the conversion of solar energy resides with the specific structure and design of the solar energy absorbing device or solar collector. This solar energy collector generally comprises a rectangular plate-like structure possessing channels or passageways therein for the circulation of the energy absorbing fluid medium. Conventionally, these channels comprise a pair of opposed expanded passageways, known as headers, which are placed at opposite ends of the panel, and are connected by a plurality of tubular passageways which are often in parallel relation with respect to each other. In addition, it is necessary to provide a temperature sensing device in association with the plate-like structure in order to accurately and efficiently determine the temperature thereof and control the circulation of said heat exchange medium throughout the system. A plurality of these temperature sensing devices are often employed depending upon the particular system in order to provide very accurate temperature control and a highly efficient system. In addition, it is often desirable to provide other means in association with the panel or plate-like structure, such as a desiccant in order to absorb moisture from the closed system wherein the plate-like structure resides. That is, the plate-like structure is generally enclosed by a glass plate and it is desirable to absorb moisture from between the panel and glass plate.
A represenatative panel structure is shown in our co-pending U.S. patent application Ser. No. 573,953, filed May 2, 1975, and now abandoned, the disclosure of which is incorporated herein by reference. In accordance with said co-pending application, it was determined that improved flow characteristics are obtainable in such a rectangular plate-like structure by a modification of the disposition of the headers wherein the headers define an angle of at least 91.degree. with respect to the direction of flow of the heat exchange medium.
The aforementioned temperature sensing devices or other means are normally associated with the panel or plate-like structure by adhering same to the outside surface of the plate-like structure in a secondary operation. This represents an inefficient method which does not obtain maximum efficiency in the solar collector system. Also, it represents a costly secondary operation which may not result in accurate temperature determination.
Accordingly, it is a principal object of the present invention to provide an improved solar energy collector system.
It is a still further object of the present invention to provide an improved solar energy collector system including at least one heat exchange panel possessing a system of internal tubular passageways wherein said panel is suitable for integral internal disposition of a second passageway system which may be used in containing a control means, such as a temperature sensing device.
Further objects and advantages of the present invention will appear hereinbelow.